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mirror of https://github.com/xcat2/xNBA.git synced 2024-12-14 07:11:32 +00:00

Provide registration mechanism for loaded images, so that we can e.g.

refer to them by name from the command line, or build them into a
multiboot module list.

Use setting image->type to disambiguate between "not my image" and "bad
image"; this avoids relying on specific values of the error code.
This commit is contained in:
Michael Brown 2007-01-11 23:43:29 +00:00
parent 79a399c05a
commit f59ad50504
4 changed files with 272 additions and 132 deletions

View File

@ -24,6 +24,7 @@
*/
#include <errno.h>
#include <alloca.h>
#include <multiboot.h>
#include <gpxe/uaccess.h>
#include <gpxe/image.h>
@ -31,6 +32,8 @@
#include <gpxe/memmap.h>
#include <gpxe/elf.h>
struct image_type multiboot_image_type __image_type;
/** Multiboot flags that we support */
#define MB_SUPPORTED_FLAGS ( MB_FLAG_PGALIGN | MB_FLAG_MEMMAP | \
MB_FLAG_VIDMODE | MB_FLAG_RAW )
@ -58,57 +61,116 @@ struct multiboot_header_info {
};
/**
* Execute multiboot image
* Build multiboot memory map
*
* @v image ELF file
* @ret rc Return status code
* @v mbinfo Multiboot information structure
* @v mbmemmap Multiboot memory map
*/
static int multiboot_execute ( struct image *image ) {
static const char *bootloader_name = "gPXE " VERSION;
struct multiboot_info mbinfo;
static void multiboot_build_memmap ( struct multiboot_info *mbinfo,
struct multiboot_memory_map *mbmemmap ) {
struct memory_map memmap;
struct multiboot_memory_map mbmemmap[ sizeof ( memmap.regions ) /
sizeof ( memmap.regions[0] ) ];
unsigned int i;
/* Populate multiboot information structure */
memset ( &mbinfo, 0, sizeof ( mbinfo ) );
/* Set boot loader name */
mbinfo.flags |= MBI_FLAG_LOADER;
mbinfo.boot_loader_name = virt_to_phys ( bootloader_name );
/* Get memory map */
get_memmap ( &memmap );
memset ( mbmemmap, 0, sizeof ( mbmemmap ) );
/* Translate into multiboot format */
memset ( mbmemmap, 0, sizeof ( *mbmemmap ) );
for ( i = 0 ; i < memmap.count ; i++ ) {
mbmemmap[i].size = sizeof ( mbmemmap[i] );
mbmemmap[i].base_addr = memmap.regions[i].start;
mbmemmap[i].length = ( memmap.regions[i].end -
memmap.regions[i].start );
mbmemmap[i].type = MBMEM_RAM;
mbinfo.mmap_length += sizeof ( mbmemmap[i] );
mbinfo->mmap_length += sizeof ( mbmemmap[i] );
if ( memmap.regions[i].start == 0 )
mbinfo.mem_lower = memmap.regions[i].end;
mbinfo->mem_lower = memmap.regions[i].end;
if ( memmap.regions[i].start == 0x100000 )
mbinfo.mem_upper = ( memmap.regions[i].end - 0x100000);
mbinfo->mem_upper = ( memmap.regions[i].end -
0x100000 );
}
mbinfo.flags |= ( MBI_FLAG_MEM | MBI_FLAG_MMAP );
}
/**
* Build multiboot module list
*
* @v image Multiboot image
* @v modules Module list to fill, or NULL
* @ret count Number of modules
*/
static unsigned int
multiboot_build_module_list ( struct image *image,
struct multiboot_module *modules ) {
struct image *module_image;
struct multiboot_module *module;
unsigned int count = 0;
for_each_image ( module_image ) {
/* Do not include kernel image as a module */
if ( module_image == image )
continue;
module = &modules[count++];
/* Populate module data structure, if applicable */
if ( ! modules )
continue;
module->mod_start = user_to_phys ( module_image->data, 0 );
module->mod_end = user_to_phys ( module_image->data,
module_image->len );
if ( image->cmdline )
module->string = virt_to_phys ( image->cmdline );
}
return count;
}
/**
* Execute multiboot image
*
* @v image Multiboot image
* @ret rc Return status code
*/
static int multiboot_exec ( struct image *image ) {
static const char *bootloader_name = "gPXE " VERSION;
struct multiboot_info mbinfo;
struct multiboot_memory_map mbmemmap[MAX_MEMORY_REGIONS];
struct multiboot_module *modules;
unsigned int num_modules;
/* Populate multiboot information structure */
memset ( &mbinfo, 0, sizeof ( mbinfo ) );
/* Set boot loader name */
mbinfo.boot_loader_name = virt_to_phys ( bootloader_name );
mbinfo.flags |= MBI_FLAG_LOADER;
/* Build memory map */
multiboot_build_memmap ( &mbinfo, mbmemmap );
mbinfo.mmap_addr = virt_to_phys ( &mbmemmap[0].base_addr );
mbinfo.flags |= ( MBI_FLAG_MEM | MBI_FLAG_MMAP );
/* Set command line, if present */
if ( image->cmdline ) {
mbinfo.flags |= MBI_FLAG_CMDLINE;
mbinfo.cmdline = virt_to_phys ( image->cmdline );
mbinfo.flags |= MBI_FLAG_CMDLINE;
}
/* Construct module list */
num_modules = multiboot_build_module_list ( image, NULL );
modules = alloca ( num_modules * sizeof ( *modules ) );
multiboot_build_module_list ( image, modules );
mbinfo.mods_count = num_modules;
mbinfo.mods_addr = virt_to_phys ( modules );
mbinfo.flags |= MBI_FLAG_MODS;
/* Jump to OS with flat physical addressing */
__asm__ __volatile__ ( PHYS_CODE ( "xchgw %%bx,%%bx\n\t"
"call *%%edi\n\t" )
__asm__ __volatile__ ( PHYS_CODE ( /* Preserve %ebp for alloca() */
"pushl %%ebp\n\t"
"call *%%edi\n\t"
"popl %%ebp\n\t" )
: : "a" ( MULTIBOOT_BOOTLOADER_MAGIC ),
"b" ( virt_to_phys ( &mbinfo ) ),
"D" ( image->entry )
: "ecx", "edx", "esi", "ebp" );
: "ecx", "edx", "esi", "memory" );
return -ECANCELED;
}
@ -191,7 +253,6 @@ static int multiboot_load_raw ( struct image *image,
/* Record execution entry point */
image->entry = hdr->mb.entry_addr;
image->execute = multiboot_execute;
return 0;
}
@ -209,21 +270,9 @@ static int multiboot_load_elf ( struct image *image ) {
if ( ( rc = elf_load ( image ) ) != 0 ) {
DBG ( "Multiboot ELF image failed to load: %s\n",
strerror ( rc ) );
/* We must translate "not an ELF image" (i.e. ENOEXEC)
* into "invalid multiboot image", to avoid screwing
* up the image probing logic.
*/
if ( rc == -ENOEXEC ) {
return -ENOTSUP;
} else {
return rc;
}
return rc;
}
/* Capture execution method */
if ( image->execute )
image->execute = multiboot_execute;
return 0;
}
@ -244,6 +293,10 @@ int multiboot_load ( struct image *image ) {
}
DBG ( "Found multiboot header with flags %08lx\n", hdr.mb.flags );
/* This is a multiboot image, valid or otherwise */
if ( ! image->type )
image->type = &multiboot_image_type;
/* Abort if we detect flags that we cannot support */
if ( hdr.mb.flags & MB_UNSUPPORTED_FLAGS ) {
DBG ( "Multiboot flags %08lx not supported\n",
@ -267,4 +320,5 @@ int multiboot_load ( struct image *image ) {
struct image_type multiboot_image_type __image_type = {
.name = "Multiboot",
.load = multiboot_load,
.exec = multiboot_exec,
};

View File

@ -1,85 +1,138 @@
#include "dev.h"
#include <gpxe/buffer.h>
#include <console.h>
#if 0
static struct image images[0] __image_start;
static struct image images_end[0] __image_end;
/*
* Print all images
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stddef.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <assert.h>
#include <vsprintf.h>
#include <gpxe/list.h>
#include <gpxe/image.h>
/** @file
*
* Executable/loadable images
*
*/
void print_images ( void ) {
struct image *image;
for ( image = images ; image < images_end ; image++ ) {
printf ( "%s ", image->name );
}
}
/** List of registered images */
struct list_head images = LIST_HEAD_INIT ( images );
/*
* Identify the image format
/** List of image types */
static struct image_type image_types[0]
__table_start ( struct image_type, image_types );
static struct image_type image_types_end[0]
__table_end ( struct image_type, image_types );
/**
* Register executable/loadable image
*
* @v image Executable/loadable image
* @ret rc Return status code
*/
static struct image * identify_image ( physaddr_t start, physaddr_t len,
void **context ) {
struct image *image;
for ( image = images ; image < images_end ; image++ ) {
if ( image->probe ( start, len, context ) )
return image;
}
return NULL;
int register_image ( struct image *image ) {
static unsigned int imgindex = 0;
/* Create image name */
snprintf ( image->name, sizeof ( image->name ), "img%d",
imgindex++ );
/* Add to image list */
list_add_tail ( &image->list, &images );
DBGC ( image, "IMAGE %p registered as %s\n", image, image->name );
return 0;
}
/*
* Load an image into memory at a location determined by the image
* format
/**
* Unregister executable/loadable image
*
* @v image Executable/loadable image
*/
int autoload ( struct dev *dev, struct image **image, void **context ) {
struct buffer buffer;
int rc = 0;
/* Prepare the load buffer */
if ( ! init_load_buffer ( &buffer ) ) {
DBG ( "IMAGE could not initialise load buffer\n" );
goto out;
}
/* Load the image into the load buffer */
if ( ! load ( dev, &buffer ) ) {
DBG ( "IMAGE could not load image\n" );
goto out_free;
}
/* Shrink the load buffer */
trim_load_buffer ( &buffer );
/* Identify the image type */
*image = identify_image ( buffer.start, buffer.fill, context );
if ( ! *image ) {
DBG ( "IMAGE could not identify image type\n" );
goto out_free;
}
/* Move the image into the target location */
if ( ! (*image)->load ( buffer.start, buffer.fill, *context ) ) {
DBG ( "IMAGE could not move to target location\n" );
goto out_free;
}
/* Return success */
rc = 1;
out_free:
/* Free the load buffer */
done_load_buffer ( &buffer );
out:
return rc;
void unregister_image ( struct image *image ) {
list_del ( &image->list );
DBGC ( image, "IMAGE %p unregistered\n", image );
}
#endif
/**
* Load executable/loadable image into memory
*
* @v image Executable/loadable image
* @ret rc Return status code
*/
int image_load ( struct image *image ) {
int rc;
assert ( image->type != NULL );
if ( ( rc = image->type->load ( image ) ) != 0 ) {
DBGC ( image, "IMAGE %p could not load: %s\n",
image, strerror ( rc ) );
return rc;
}
return 0;
}
/**
* Autodetect image type and load executable/loadable image into memory
*
* @v image Executable/loadable image
* @ret rc Return status code
*/
int image_autoload ( struct image *image ) {
struct image_type *type;
int rc;
for ( type = image_types ; type < image_types_end ; type++ ) {
rc = type->load ( image );
if ( image->type == NULL )
continue;
if ( rc != 0 ) {
DBGC ( image, "IMAGE %p (%s) could not load: %s\n",
image, image->type->name, strerror ( rc ) );
return rc;
}
return 0;
}
DBGC ( image, "IMAGE %p format not recognised\n", image );
return -ENOEXEC;
}
/**
* Execute loaded image
*
* @v image Loaded image
* @ret rc Return status code
*/
int image_exec ( struct image *image ) {
int rc;
assert ( image->type != NULL );
if ( ( rc = image->type->exec ( image ) ) != 0 ) {
DBGC ( image, "IMAGE %p could not execute: %s\n",
image, strerror ( rc ) );
return rc;
}
/* Well, some formats might return... */
return 0;
}

View File

@ -30,6 +30,8 @@
#include <gpxe/image.h>
#include <gpxe/elf.h>
struct image_type elf_image_type __image_type;
typedef Elf32_Ehdr Elf_Ehdr;
typedef Elf32_Phdr Elf_Phdr;
typedef Elf32_Off Elf_Off;
@ -40,7 +42,7 @@ typedef Elf32_Off Elf_Off;
* @v image ELF file
* @ret rc Return status code
*/
static int elf_execute ( struct image *image __unused ) {
static int elf_exec ( struct image *image __unused ) {
return -ENOTSUP;
}
@ -63,7 +65,7 @@ static int elf_load_segment ( struct image *image, Elf_Phdr *phdr ) {
/* Check segment lies within image */
if ( ( phdr->p_offset + phdr->p_filesz ) > image->len ) {
DBG ( "ELF segment outside ELF file\n" );
return -ERANGE;
return -ENOEXEC;
}
/* Find start address: use physical address for preference,
@ -75,7 +77,7 @@ static int elf_load_segment ( struct image *image, Elf_Phdr *phdr ) {
dest = phdr->p_vaddr;
if ( ! dest ) {
DBG ( "ELF segment loads to physical address 0\n" );
return -ERANGE;
return -ENOEXEC;
}
buffer = phys_to_user ( dest );
@ -117,13 +119,17 @@ int elf_load ( struct image *image ) {
return -ENOEXEC;
}
/* This is an ELF image, valid or otherwise */
if ( ! image->type )
image->type = &elf_image_type;
/* Read ELF program headers */
for ( phoff = ehdr.e_phoff , phnum = ehdr.e_phnum ; phnum ;
phoff += ehdr.e_phentsize, phnum-- ) {
if ( phoff > image->len ) {
DBG ( "ELF program header %d outside ELF image\n",
phnum );
return -ERANGE;
return -ENOEXEC;
}
copy_from_user ( &phdr, image->data, phoff, sizeof ( phdr ) );
if ( ( rc = elf_load_segment ( image, &phdr ) ) != 0 )
@ -132,7 +138,6 @@ int elf_load ( struct image *image ) {
/* Fill in entry point address */
image->entry = ehdr.e_entry;
image->execute = elf_execute;
return 0;
}
@ -141,4 +146,5 @@ int elf_load ( struct image *image ) {
struct image_type elf_image_type __image_type = {
.name = "ELF",
.load = elf_load,
.exec = elf_exec,
};

View File

@ -4,37 +4,44 @@
/**
* @file
*
* Executable/loadable image formats
* Executable/loadable images
*
*/
#include <gpxe/tables.h>
#include <gpxe/list.h>
#include <gpxe/uaccess.h>
struct image_type;
/** An executable or loadable image */
struct image {
/** Name */
char name[16];
/** List of registered images */
struct list_head list;
/** Command line to pass to image */
const char *cmdline;
/** Raw file image */
userptr_t data;
/** Length of raw file image */
size_t len;
/** Execute method
*
* Filled in by the image loader. If NULL, then the image
* cannot be executed.
*/
int ( * execute ) ( struct image *image );
/** Entry point */
physaddr_t entry;
/** Command line to pass to image */
const char *cmdline;
/** Image type, if known */
struct image_type *type;
};
/** An executable or loadable image type */
struct image_type {
/** Name of this image type */
char *name;
/** Load image into memory
/**
* Load image into memory
*
* @v image Executable/loadable image
* @ret rc Return status code
@ -44,15 +51,23 @@ struct image_type {
* information it may require later (e.g. the execution
* address) within the @c image structure.
*
* The method should return -ENOEXEC if and only if the image
* is not in the correct format. Other errors will be
* interpreted as "I claim this image format, but there's
* something wrong with it that makes it unloadable". In
* particular, returning -ENOEXEC will cause the image probing
* code to try the next available image type, while returning
* any other error will terminate image probing.
* If the file image is in the correct format, the method must
* update @c image->type to point to its own type (unless @c
* image->type is already set). This allows the autoloading
* code to disambiguate between "this is not my image format"
* and "there is something wrong with this image". In
* particular, setting @c image->type and then returning an
* error will cause image_autoload() to abort and return an
* error, rather than continuing to the next image type.
*/
int ( * load ) ( struct image *image );
/**
* Execute loaded image
*
* @v image Loaded image
* @ret rc Return status code
*/
int ( * exec ) ( struct image *image );
};
/** An executable or loadable image type */
@ -68,4 +83,16 @@ struct image_type {
*/
#define __default_image_type __table ( struct image_type, image_types, 02 )
extern struct list_head images;
/** Iterate over all registered images */
#define for_each_image( image ) \
list_for_each_entry ( (image), &images, list )
extern int register_image ( struct image *image );
extern void unregister_image ( struct image *image );
extern int image_load ( struct image *image );
extern int image_autoload ( struct image *image );
extern int image_exec ( struct image *image );
#endif /* _GPXE_IMAGE_H */